If your NAS has redundancy and the network between the NAS and the PVE cluster has redundancy and all that has power redundancy it can be totally fine to use that as HA setup in practice.
It's just that using that there are more components involved to provide the basic system, like the network between each cluster node and the storage. Avoiding that avoids failure potential, i.e., a switch that is not there cannot fail. If you want, or need, to use the extra component and thus the switch, or network cable, then you should at least ensure that the whole thing can still work if one switch or cable breaks.
This is mostly relevant for a green field project, as with some good design you can use that to reduce components, thus cost, while maybe even increasing the redundancy and reliability of your system. If you already got the NAS, it might well be the poorer (financial) decision to switch away from it.
To be able to give you more specific answer what would be best more confidently, one would need to know much more details. But, I think that's not a good fit for this thread, and it's also a lot of work to gather that info, interpret it and write the answer, so also not the best fit for this community forum (not saying you shouldn't try it, just don't be surprised if nobody replies on it).
In general, I'd recommend you to set up a test system and try out everything you want to hedge against and what seems realistic to happen in your environment.
Oh, and just a reminder: HA is to improve uptime (i.e., availability) on partial failure, but not a backup & recovery strategy, which one always should have, at least if one cares about the data (or your payroll depends on that).
It's just that using that there are more components involved to provide the basic system, like the network between each cluster node and the storage. Avoiding that avoids failure potential, i.e., a switch that is not there cannot fail. If you want, or need, to use the extra component and thus the switch, or network cable, then you should at least ensure that the whole thing can still work if one switch or cable breaks.
This is mostly relevant for a green field project, as with some good design you can use that to reduce components, thus cost, while maybe even increasing the redundancy and reliability of your system. If you already got the NAS, it might well be the poorer (financial) decision to switch away from it.
To be able to give you more specific answer what would be best more confidently, one would need to know much more details. But, I think that's not a good fit for this thread, and it's also a lot of work to gather that info, interpret it and write the answer, so also not the best fit for this community forum (not saying you shouldn't try it, just don't be surprised if nobody replies on it).
In general, I'd recommend you to set up a test system and try out everything you want to hedge against and what seems realistic to happen in your environment.
Oh, and just a reminder: HA is to improve uptime (i.e., availability) on partial failure, but not a backup & recovery strategy, which one always should have, at least if one cares about the data (or your payroll depends on that).
